Prota 7(2): Timbers/Bois d’œuvre 2
Ann. Bot. 2: 571, t. 16–17 (1806).
2n = 32
Ackee, akee, akee apple, savory akee tree (En). Aki, fisanier, blighia savoureuse, fausse anacarde, pommier d’aki, arbre fricassé (Fr). Castanheiro de Africa, castanha de Africa, huevo vegetal castanha (Po).
Origin and geographic distribution
Blighia sapida occurs naturally from Senegal to Cameroon and Equatorial Guinea, and possibly also in Gabon. It is commonly planted in its natural area of distribution, as fruit tree and ornamental shade tree. It has been introduced in many other tropical countries and in some subtropical regions such as Florida (United States) and is widely cultivated as fruit and ornamental tree in India and tropical America. It had already been introduced in tropical America by the end of the 18th century, and has since become locally naturalized.
Wood of Blighia sapida, known as ‘achin’ or ‘tsana’, is mainly used for light construction and furniture, but sometimes also for casks, boxes, crates, food containers, packing cases, tool handles, paddles, pestles, mortars, handicrafts, carving and turnery. It is suitable for interior trim, joinery and railway sleepers. In Ghana, it is used as a substitute for niangon (Heritiera utilis (Sprague) Sprague). The wood is also used as firewood and for charcoal production.
Blighia sapida is commonly planted as ornamental shade tree. It is considered useful for soil improvement and erosion control. In traditional medicine, sap from terminal buds is instilled in the eyes to treat ophthalmia and conjunctivites. Bark and leaf decoctions are administered to treat oedema, intercostal pain, dysentery and diarrhoea. In Ghana, bark ground-up with capsicum pepper (Capsicum annuum L.) is rubbed on the body as stimulant and pulp of ground leafy twigs is rubbed on the forehead to treat migraine. In Côte d’Ivoire and Nigeria, ground leaves are applied as a paste together with plant salts to treat yaws and ulcers. In traditional medicine in Côte d’Ivoire, Blighia sapida is widely used for the treatment of yellow fever, epilepsy and oedema, and as a laxative and diuretic. The seeds are taken in Ghana to control nausea and vomiting. In Benin, leaves are used in the treatment of fever and vertigo, and twigs to treat hepatitis, cirrhosis and amygdalitis. In Togo, decoctions of bark or fruit walls are applied to wounds, and the fruit pulp to treat whitlow. Pounded bark is administered as an antidote to snake and scorpion bites, and pounded seeds to treat stomach complaints. Aqueous seed extracts are administered to expel parasites in Brazil. The pounded fruit is used as fish poison. Green fruits lather in water and are used by the Krobo people of Ghana as soap for washing and as a mordant for dyeing. Dried fruit husks are rich in potash and the ashes are used in making soap. Seeds of Blighia sapida yield a yellowish oil, believed to be edible. In Nigeria the seeds are used in making traditional soap.
Mature seed arils are eaten. They are not largely consumed in Africa, but considered a delicacy in some other parts of the world where Blighia sapida has been introduced. Ackee is also the national fruit of Jamaica. Boiled arils are an ingredient of a popular traditional dish in Jamaica, together with salt fish. In West Africa arils are sometimes eaten raw, fried or roasted. However, the arils of unripe seeds are toxic, as well as the seeds. An ink for tattoos is made from the seeds.
Production and international trade
Blighia sapida timber has no importance on the international market, and even local importance seems to be limited because in many areas within its distribution area it occurs in low densities. However, in a study in south-western Nigeria, Blighia sapida was found to be one of the most commonly logged and processed timber species.
The arils are commercially traded, mainly from Jamaica to American and European markets. Canned arils form the major product, in 2001 about 1.7 million kg, with frozen arils much less important with 13,000 kg. Orchards of Blighia sapida have also been established in Florida (United States), Mexico and Costa Rica. In 2005 total production of arils was valued at US$ 400 million. In Africa, the trade is local. In 1992 in northern Côte d’Ivoire, the price of 3 arils was about 10 FCFA.
The heartwood of Blighia sapida is orange-brown or reddish brown, and distinctly demarcated from the whitish sapwood. The texture is moderately coarse. The wood has little lustre. It is moderately heavy and hard. It is easy to work with both machine and hand tools. The wood moulds and sands well and takes an attractive finish. It is suitable for turnery. It is moderately durable and is quite resistant to termite attack.
The composition of 100 g of raw aril is approximately: water 58 g, protein 9 g, fat 19 g, carbohydrate 10 g, fibre 3.5 g, Ca 83 mg, P 98 mg, Fe 5.5 mg, thiamin 0.1 mg, riboflavin 0.2 mg, niacin 3.7 mg and ascorbic acid 65 mg.
A water-soluble and heat-stable toxic compound, hypoglycin A, is present in the aril of unripe seeds, as well as in the seed and in the pinkish to reddish tissue at the base of the aril. The Jamaican vomiting sickness is associated with this compound and is characterized by vomiting, generalized weakness, altered consciousness and sometimes even death. Hypoglycemia and depression of the central nervous system are common. The aril of fully ripe seeds after natural dehiscence of the fruit is nearly free of the toxic compound. The consumption of unripe seed arils has probably caused many cases of encephalopathy in children in Burkina Faso and other West African countries. The seeds contain about 26% of oil which is suitable for industrial applications.
Extracts of unripe fruits produced neutropenia and thrombocytopenia in mice, suggesting that they may be useful in the treatment of diseases such as chronic myeloid leukaemia, essential thrombocythaemia and polycythaemia.
Usually evergreen, dioecious, small to medium-sized tree up to 25(–30) m tall; bole branchless for up to 15 m and straight and cylindrical, but often much shorter and crooked or twisted, up to 80(–120) cm in diameter, often with small buttresses; bark surface usually smooth but with lenticels in horizontal lines, grey to pale brown, inner bark granular, yellow to brown or pinkish, often mottled orange; crown dense and rounded; young twigs grooved, yellow-orange hairy, becoming glabrous. Leaves alternate, paripinnately compound with 3–5 pairs of leaflets; stipules absent; petiole 0.5–2.5 cm long, slightly winged, rachis up to 20 cm long; petiolules stout, up to 6 mm long; leaflets opposite, elliptical to obovate, 5–15 cm × 3.5–8 cm, lowest pair smallest, cuneate to rounded at base, rounded to short-acuminate at apex, margins entire or slightly wavy, papery or thinly leathery, dark green, slightly hairy below, pinnately veined with 8–14 pairs of lateral veins. Inflorescence an axillary, slender false raceme up to 20 cm long, hairy. Flowers probably functionally unisexual, regular, 5-merous, greenish white to greenish yellow, sweet-scented; pedicel up to 6 mm long, elongating up to 10 mm in fruit; calyx with tube about as long as lobes, 2–3 mm long; petals free, rhomboid, 3–4 mm long, hairy, with a 2-lobed scale on the inner face; stamens 6–10, free, filaments up to 6 mm long, hairy in lower part; ovary superior, hairy, usually 3-lobed and 3-celled, style short; male flowers with rudimentary ovary, female flowers with reduced stamens. Fruit an obovoid to pear-shaped capsule 3.5–10 cm × 3–5 cm, slightly 3-lobed, yellow to red when ripe, glabrous, dehiscing with 3 woody valves hairy inside, usually 3-seeded. Seeds ovoid, 2–2.5 cm long, glossy black, with cream-coloured to yellow cup-shaped aril up to 2 cm long at base. Seedling with hypogeal germination; epicotyl c. 15 cm long, hairy; first 2 leaves opposite, with 3 elliptical or obovate leaflets up to 10 cm × 3.5 cm.
Other botanical information
Blighia comprises 3 species and originates from tropical Africa. Blighia sapida can be distinguished from the other two species by its large fruits with rounded lobes.
Wood-anatomical description (IAWA hardwood codes):
Growth rings: 2: growth ring boundaries indistinct or absent. Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; 23: shape of alternate pits polygonal; 25: intervessel pits small (4–7 μm); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; (36: helical thickenings in vessel elements present); (37: helical thickenings throughout body of vessel element); (38: helical thickenings only in vessel element tails); 42: mean tangential diameter of vessel lumina 100–200 μm; 46: ≥ 12 rays per mm. Mineral inclusions: 136: prismatic crystals present; 138: prismatic crystals in procumbent ray cells.
(S. N’Danikou, P.E. Gasson & E.A. Wheeler)
Growth and development
Initial growth of Blighia sapida is fast on moderately fertile soils. Seedlings grow best in gaps in the forest canopy, with a mean annual height increment of 70 cm. Blighia sapida is classified as a non-pioneer light demander. It has an extensive rooting system. In pure stands at a spacing of 3.5 m × 3.5 m in northern Côte d’Ivoire, the fastest growing trees reached 4 m tall 3 years after planting and the canopy was closed after 4.5 years. In Cameroon, young trees raised from seed started flowering after 5 years and first fruits developed after 7 years. In Florida, trees raised from seedlings start producing fruit after 3–6 years, while grafted trees produce fruit in 1–2 years.
Blighia sapida has been recorded to flower twice a year, first at the end of the dry season and a second time at the end of the rainy season. Fruits mature about 6 months after flowering, but in orchards fruit development may take only 2 months. It has been recorded that only about 4% of female or apparently bisexual flowers develop into a mature fruit. All-year-round flowering and fruiting have been recorded in tropical America. The flowers are pollinated by insects such as bees. Although trees in the natural area of distribution seem to be dioecious (male and female flowers on different trees), it has been reported in Jamaica that they are andro-monoecious (with male and bisexual flowers produced on the same tree). The seeds are probably dispersed by animals such as large birds and monkeys.
Blighia sapida occurs most commonly in semi-deciduous forest, but can also be found in evergreen forest as well as in forest outliers in savanna regions. In Côte d’Ivoire, it is most common in the transition zone between dry and moister forest and in gallery forest. It has been planted successfully in villages in much drier zones in Mali and Burkina Faso. The natural habitat of the species is obscured by the common planting around villages and further spread from there into the forest. It prefers well-drained deep fertile soils, but occurs also on non-fertile sandy soils and limestone. In drier regions it is often found on termite mounds. It does not tolerate waterlogged soils and cannot withstand flooding. It shows some resistance to fire.
Propagation and planting
Generally, Blighia sapida regenerates fairly well naturally. The weight of a seed is about 3 g. Seeds are sensitive to desiccation and are considered short-lived. It is recommended to sow them within a few days after extraction from the fruit. However, seeds can be kept for 3 months in moist storage at 21°C. Germination starts after 2–4 weeks, with a germination rate of 80%. In Florida, seeds are sown in germination boxes and germination is said to take normally 2–3 months. Seedlings should be watered regularly in the nursery before transplanting. It is recommended to transplant in full sunlight and at a spacing of 4 m for timber production and 6–9 m for fruit production.
For planting, Blighia sapida is usually propagated by seed, but cuttings can also be used; these readily develop roots under proper conditions. Propagation by grafting and air layering was also successful.
In areas with occasional flooding, mounds of 60–90 cm high are made before transplanting of seedlings to ensure plant survival. In Florida and other regions where Blighia sapida is planted for commercial fruit production, young trees are fertilized every 1–2 months during the first year. Topping the main shoot at a height of about 5 m is recommended to facilitate fruit harvesting. It is recommended to control tree form by pruning several times when the tree is grown for timber production. Trees often sprout vigorously from stumps.
In Benin, the most common management practices to improve fruit production are pruning, protection against livestock, fire protection, mulching of seedlings and saplings, and association with annual crops. In northern Côte d’Ivoire, trees have generally a private owner, whereas most other trees are collective property.
Diseases and pests
In Florida, an attack by Verticillium dahliae has been recorded, causing wilt and dieback. In Jamaica, stem galls are common.
Arils for fresh consumption should be picked from dehisced fruits, which ensures that the seeds and arils are fully ripe and that arils do not contain serious amounts of toxin. Another appropriate method is to collect unopened but ripe fruits from the tree and lay them on racks in the sun. Arils can be harvested from the fruits when they have opened after about 3 days.
In Florida, a tree may produce 45–68 kg of fruits per year.
There seems to be no reason to consider Blighia sapida to be under threat of genetic erosion. It is quite widespread and is commonly planted. Research in Benin showed that Blighia sapida has moderate levels of genetic diversity in Benin and little differentiation among populations and climatic zones. Nine distinct criteria, mostly related to fruit characteristics, have been used to differentiate between types.
In Jamaica, some different fruit types of Blighia sapida have been developed, mainly differing in the aril, which may be soft and yellow or firm and cream-coloured.
Wood of Blighia sapida is currently not commercially important, but it is a multipurpose tree, being a source of edible fruits (arils) and traditional medicine, and being popular for planting as ornamental shade tree. Blighia sapida is a nice ornamental tree, especially when decorated with the brightly coloured fruits. It is also considered useful for planting to improve soil fertility and to reduce erosion through its large rooting system. In 2003 Blighia sapida emerged as a high-priority species for domestication in Benin after a national survey.
Extensive research has been carried out on the toxicity of different parts of the fruit. The edible arils certainly offer possibilities for economic development in tropical Africa, but lessons learnt from tropical America and Burkina Faso regarding the toxicity of compounds should be taken into serious consideration. Educational campaigns are needed to prevent fatalities. More pharmacological studies are recommended in view of the wide applications of different plant parts in traditional medicine. The seed oil is promising for industrial use, especially as lubricant and speciality surfactant.
• Akintayo, E.T., Adebayo, E.A. & Arogundade, L.A., 2002. Chemical composition, physicochemical and functional properties of akee (Blighia sapida) pulp and seed flours. Food Chemistry 77(3): 333–336.
• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome troisième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 334 pp.
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• Ekué, M.R.M., Gailing, O., Finkeldey, R. & Eyog-Matig, O., 2009. Indigenous knowledge, traditional management and genetic diversity of the endogenous agroforestry species ackee (Blighia sapida) in Benin. ISHS Acta Horticulturae 806: International symposium on underutilized plants for food security, nutrition, income and sustainable development. pp. 655–661.
• Janick, J. & Paull, R.E. (Editors), 2006. Encyclopedia of fruit and nuts. CABI, Wallingford, United Kingdom. 954 pp.
• Meda, H.A., Diallo, B., Buchet, J.P., Lison, D., Barennes, H., Ouangré, A., Sanou, M., Cousens, S., Tall, F. & van de Perre, P., 1999. Epidemic of fatal encephalopathy in preschool children in Burkina Faso and consumption of unripe ackee (Blighia sapida) fruit. The Lancet 353: 536–540.
• Omobuwajo, T.O., Sanni, L.A. & Olajide, J.O., 2000. Physical properties of ackee apple (Blighia sapida) seeds. Journal of Food Engineering 45: 43–48.
• Oteng-Amoako, A.A. (Editor), 2006. 100 tropical African timber trees from Ghana: tree description and wood identification with notes on distribution, ecology, silviculture, ethnobotany and wood uses. 304 pp.
• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.
• World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ resources/databases/ agroforestree. Accessed October 2009.
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (Editors), 2006. Flore analytique du Bénin. Backhuys Publishers, Leiden, Netherlands. 1034 pp.
• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 pp.
• Barceloux, D.G., 2009. Akee fruit and Jamaican vomiting sickness (Blighia sapida Koenig). Disease-a-Month 55(6): 318–326.
• Crane, J.C. & Balerdi, C.F., 2008. Ackee growing in the Florida home landscape. [Internet] Fact Sheet HS–1128, Horticultural Sciences Department, Florida Cooperative Extension Service, University of Florida, Gainesville, United States. http://edis.ifas.ufl.edu/HS378. Accessed October 2009.
• Fouilloy, R. & Hallé, N., 1973. Sapindacées. Flore du Cameroun. Volume 16. Muséum National d’Histoire Naturelle, Paris, France. 202 pp.
• Gardner, M.T., Williams, L.A.D., The, T.L., Fletcher, C.K., Singh, P.D.A., Wharfe, G., Choo-kang, E., Sawh, R.N. & Rickards, E., 1996. Extracts from Blighia sapida (Koenig) produce neutropenia and thrombocytopenia in mice. Phytotherapy Research 10(8): 689–691.
• Goldson, A., 2005. The ackee fruit (Blighia sapida) and its associated toxic effects. The Science Creative Quarterly (4): 2009. [Internet] http://nsdl.org/ resource/2200/ 20070529143108499T. Accessed October 2009.
• Hawthorne, W.D., 1995. Ecological profiles of Ghanaian forest trees. Tropical Forestry Papers 29. Oxford Forestry Institute, Department of Plant Sciences, University of Oxford, United Kingdom. 345 pp.
• Hawthorne, W. & Jongkind, C., 2006. Woody plants of western African forests: a guide to the forest trees, shrubs and lianes from Senegal to Ghana. Kew Publishing, Royal Botanic Gardens, Kew, United Kingdom. 1023 pp.
• Irvine, F.R., 1961. Woody plants of Ghana, with special reference to their uses. Oxford University Press, London, United Kingdom. 868 pp.
• Keay, R.W.J., 1958. Sapindaceae. In: Keay, R.W.J. (Editor). Flora of West Tropical Africa. Volume 1, part 2. 2nd Edition. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 709–725.
• Keay, R.W.J., 1989. Trees of Nigeria. A revised version of Nigerian trees (1960, 1964) by Keay, R.W.J., Onochie, C.F.A. & Stanfield, D.P. Clarendon Press, Oxford, United Kingdom. 476 pp.
• Kennedy, D.J., 1936. Forest flora of southern Nigeria. Government Printer, Lagos. 277 pp.
• Kyari, M.Z., 2008. Extraction and characterization of seed oils. International Agrophysics 22: 139–142.
• Liu, K., Eastwood, R.J., Flynn, S., Turner, R.M. & Stuppy, W.H., 2008. Blighia sapida. [Internet] Seed Information Database Release 7.1, May 2008. http://data.kew.org/ sid/SidServlet?ID=3433&Num=BAG. Accessed October 2009.
• McMillan, R.T., Graves, W.R. & Wood, T.F., 2003. Dieback caused by Verticillium dahliae on Blighia sapida. Proceedings Florida State Horticultural Society 116: 6–8.
• Morton, J.F., 1987. In: Fruits of warm climates. [Internet] Julia F. Morton, Miami, United States. 505 pp. http://www.hort.purdue.edu/ newcrop/morton/ akee.html. Accessed October 2009.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Oke, S.O. & Oyedare, P.F., 2008. Effects of logging activities on the floristics and structure of the vegetation in Isokan area of Southwestern Nigeria. Journal of Plant Sciences 3(2): 157–167.
• Vivien, J. & Faure, J.J., 1996. Fruitiers sauvages d’Afrique: espèces du Cameroun. Ministère Français de la Coopération, Paris, France & CTA, Wageningen, Netherlands. 416 pp.
Sources of illustration
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (Editors), 2006. Flore analytique du Bénin. Backhuys Publishers, Leiden, Netherlands. 1034 pp.
Correct citation of this article:
Asamoah, A., Antwi-Bosiako, C., Frimpong-Mensah, K., Atta-Boateng, A., Montes, C.S. & Louppe, D., 2010. Blighia sapida K.D.Koenig. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). Prota 7(2): Timbers/Bois d’œuvre 2. [CD-Rom]. PROTA, Wageningen, Netherlands.
wild and planted
1, part of twig with leaf and inflorescence; 2, male flower; 3, female flower; 4, dehisced fruit showing seeds.
Source: Flore analytique du Bénin
obtained from TopTropicals
plantation of 9 years
plantation of 11 years
wood in tangential section
wood in transverse section